Opening up too much of the Alaska reserve, whose oil deposits have been vastly overestimated, would not solve the nation's long-term energy demands.

The National Petroleum Reserve-Alaska just isn't what it used to be — or rather, what we thought it was. Until about two years ago, the 23-million-acre spread of land was thought to hold a treasure-trove of 10.6 billion barrels of black gold. Then research by the U.S. Geological Survey brought the figure way down, to less than a tenth of that amount.

Yet the reserve is rich in other features, among them wildlife and the fragile ecosystems in which it lives. Interior Secretary Ken Salazar wisely recognized both kinds of resources in drafting the first comprehensive plan for the reserve. The proposal, which must go through a 30-day review period before being finalized, would allow oil exploration on slightly more than half of the land, where close to three-fourths of the recoverable oil is located, and set aside the rest as environmentally important conservation areas.

Alaska's political representatives complain that too little land would be left for oil drilling that could, they say, create jobs and power the nation. But they're overlooking both the law and the limits of the reserve's oil deposits.

The Indiana-sized spread in northwestern Alaska was originally called the Naval Petroleum Reserve; it was set aside during the 1920s as the Navy was converting from coal to oil power, with the idea that the resources would be available to the military if needed. Authority over the land was eventually transferred to the Interior Department, the reserve was renamed, and in 1976 Congress passed a law that required the agency to balance mineral exploration and wilderness preservation. Salazar's plan would accomplish that. It also allows for an oil pipeline across the unprotected stretches of the reserve.

Meanwhile, industry interest in the reserve has diminished. Oil rights were first leased in 1982 and now cover 1.5 million acres, but so far no oil is being produced, though that might happen over the next few years in the eastern portion. Some leases have been allowed to lapse with no exploration, and others drew little response from the energy companies. Industry leaders know that the far richer source of oil lies under the Arctic seas. The waters of the Chukchi Sea alone are believed to cover a store of up to 20 billion barrels of oil, well over 20 times the amount in the reserve — though we don't believe that Shell Oil, which has been given conditional approval to drill there, has yet developed a plan that contains sufficient environmental protections.

No amount of drilling will solve the long-term energy demands of the nation, but opening almost every part of the reserve to oil exploration certainly isn't the answer.